<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script type="text/javascript">
    function Tiger(){
        this.color="yellow";
        this.leg=4;
        this.act="猛虎下山";
    }
    Tiger.prototype.weight=270;
    var wast=new Tiger();
    console.log(wast);
</script>
</body>
</html>